SMART QUILL

Contents Introduction Motive History Accelerometer sensors Basic theory of operation Architecture and working Advantages & disadvantages Application Conclusion

Introduction Smart Quill is a computer housed within a pen which

allows user to do what a normal personal organizer does.

A pen that can remember the words that it is used to write and then transform them into computer text

It is claimed to be the biggest revolution in handwriting

since the invention of the pen.

Motive Introduction of handheld computers

Size of keyboards and screens that need constant cursor controls to read simple text .

Smart Quill has solved some of the problems.

History Lindsay Williams of Microsoft Research's Cambridge UK lab is

the inventor of Smart Quill.

It has been developed by world-leading research laboratories run by BT (formerly British Telecom) at Martlesham, eastern England.

Accelerometer Sensors Accelerometer sensors measure the acceleration

experienced by the sensor and anything to which the it is directly attached.

The signal from an accelerometer sensor can be separated into two signals : acceleration from gravity and external acceleration.

Basic theory of operation Accelerometer sensors convert either linear or angular

acceleration to an output signal .It works on the principle of Newton's second law of motion

f – force in newton m- mass in kg a- acceleration in m/sec^2

Includes force from external acceleration, the force from damping and the restorative force of the spring .

Diagram of differential capacitive layout.

Architecture and working

LVDT signal conditioner IC An LVDT is a set of three wire coils collinear with each other.

One central coil is the primary of the transformer, and the other two are secondary coils

Anti –aliasing filter The anti-aliasing filters used are four pole butter worth filters which

removes noise from the signal and outputs signal of desired bandwidth.

Analog to digital converter In the analog board 4 channel 16-bit successive-approximation

switched capacitor ADC

Timing Diagram of ADC Functions

Digital board The primary function of the digital PCB is converting the serial

digital data from the ADC to a parallel digital signal suitable for passing into a computer.

The key element on the digital board is a first-in-first-out (FIFO) buffer which has clocked serial input and an 8-bit parallel output .

The sixteen bits of serial data fill up two successive bytes in the FIFO memory.

74LS244 line driver/ line-receiver on the digital board receives the ADC data and locks signals from the analog board and sends them directly to the FIFO input.

A clock on the digital board is the source for the channel counter and the read/convert signal for the ADC

Program overview The software is the final component of the complete

accelerometer sensor.

The program stores and displays the acceleration data from the accelerometer sensor

There are three sections to the program. Collecting the data Data processing Data display

Data Acquisition The connections in the parallel port of a computer are divided

into several different groups: eight data lines, four control lines, four status lines, and the remaining are grounds.

The first step to data acquisition is checking the FIFO status lines.

When the FIFO has data available, a parallel port control line connected to the read pin of FIFO is switched, loads the next byte of data through the data lines.

If there is no data in the FIFO, the program defers to kill time.

Data display and storage Allows user to store and display the data. The user

has the option of saving the acquired data either as the unfiltered raw data, or the filtered output data.

Due to the constraints of the two-dimensional computer screen, the user can select only two accelerometer channels to display at any one time: one on the horizontal axis and one on the vertical axis.

Communication with other devices

Smart quill hooks up to a PC via a cable and electronic docking station called an "inkwell".

It can also be connected to printer, modem or mobile phones to send data electronically

Future models could receive e-mails and pager messages via a wireless messaging system

Memory Smart Quill has 4MB EEPROM memory. The data is stored in the memory on the pen

until it is uploaded to the personal computer.

Power Smart Quill is powered by AAA battery

It will run for about 25hrs on a single AAA battery. The pen exhibits automatic power on/off system

Advantages Smart quill can read on any flat surface (not only on

paper)

It is password protected.

Highly convenient and portable.

It can link to modems, printer etc

Power saving

Disadvantages It has accelerometer errors.

It is inconvenient for persons with hand tremors.

Bigger size than a normal pen.

Errors are introduced in the system due to thermal variations in the spring.

Applications Diary Calculator Contact database Note taker Calendar Receive mobile and pager messages. Video conferencing Classroom lectures

Conclusion Smart quill will be a boon to the users writing in traditional languages.

. It supports two factors: small size and convenient use. The estimated cost of this futuristic pen is around $200.

Three dimensional sensors are developed and with their implementation, free writing in air can be achieved. The future of Smart Quill ensures all computation power the user needs right inside the pen.

References R.Baron, R. Plamondon, “Acceleration measurement with an

instrumented for sign verification and handwriting analysis” , IEEE Trans . Vol IM-38

E.Millien, C.Roux, “Users input to design of a “communicating pen”, Smart Objects Conference, 2003

http://www.mtl.mit.edu/researchgroups/MEngTP/Graham_Thesis.pdf

http://sites.google.com/site/sensecam/smartquill. www.smartquill.com

http://www.analog.com/static/imported-files/data_sheets/AD974.pdf